Method and apparatus for the manufacture of annular structures having a filiform element helically wound about an imaginary axis



May 17, 1966 M. VANZO 3,251,334

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 1963 7 Sheets-Sheet 1 Q: k Q k a W INVENTOR MarceZZo VamzaATTORNEY6' May 17, 1966 M. VANZO 3,

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 1963 '7 Sheets-Sheet 2 INVENTOR ATTORNEY' May 17, 1966 M. VANZO3,251,384

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELIGALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 19625 7 Sheets-Sheet 3 M MM 7WWW1W J 4/; w I -WrH ?HwnHm W i Il! Ill ii I l il A v i; I I46 35 I NVEN TOR Marcella Vmza ORNEYS May 17,1966 M. VANZO 3,251,384

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 1963 7 Sheets-Sheet 4 MzrceZZa Va/zza ATTORNEYcS' May 17, 1966M. VANZO 3,251,384

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 1963 '7 SheetsSheet 5 INVENTOR Mameflo Van/:0

ORNEYS 3,251,384 ULAR M. VANZO May 17, 1966 METHOD AND APPARATUS FOR THEMANUFACTURE OF ANN STRUCTURES HAVING A FILIF'ORM ELEMENT HELICALLY WOUNDABOUT AN IMAGINARY AXIS 1963 '7 Sheets-Sheet 6 Original Filed July 1,

INVENTOR Mamefilo Vmzza ATTORNEYS May 17, 1966 M. VANZO 3,251,384

METHOD AND APPARATUS FOR THE MANUFACTURE OF ANNULAR STRUCTURES HAVING AFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY AXIS Original FiledJuly 1, 1963 7 Sheets-Sheet 7 @2'0 CYLINDER 24 INVENTOR {62' M9 g6MarceZZo Vzrzzo ORNEYS United States Patent 3,251,384 METHOD ANDAPPARATUS FoR THE MANUFAC.

TURE OF ANNULAR STRUCTURES HAVING A v FILIFORM ELEMENT HELICALLY ABOUTAN IMAGINARY AXIS Marcello Vanzo, Milan, Italy, assignor to PirelliS.p.A., Milan, Italy Continuation of abandoned application Ser. No.291,855, July 1, 1963. This application Mar. 18, 1965, Ser. No. 444,912

Claims priority, application Italy, July 9, 1962, Patent 671,249 17Claims. (Cl. 140-71) This application is a continuation of applicationSerial No. 291,855 filed July 1, 1963, now abandoned.

The present invention relates to the manufacture of annular structuresconstituted by a single elementary or composite continuous filiformelement helically wound about an imaginary circular axis, and inparticular it pertains to making twisted-type coreless grommets forreinforcing the beads of pneumatic tires.

A co-pending application, Serial No. 273,413 filed April 16, 1963 of thesame applicant, describes a method and a practical form af apparatus toobtain annular structures of the above-indicated type based on the useof an auxiliary core in the form of a continuous flexible ring of agenerally circular cross section having a movement of rotation about itsown axis of symmetry and a movement of rotation about an axis passingthrough the centers of its cross sections. While this method gives goodresults in the manufacture of annular structures having a diametergreater than 30 cm., it-has been found to be not completely satisfactorywith structures of smaller diameter, in particular in view of thedifiiculty encountered in rotating a core having a reduced cross sectionabout the axis passing through the center of its cross sections.

The principal object of the present invention is the provision of a newand substantially different method for the automatic and continuousmanufacture of annular structures constituted of an elementary orcomposite continuous filiform element whereby an end of the filiformelement is at first directly or indirectly securedto one face of a dischaving a central eyelet provided with a lateral inlet. Then, the disc orcircular plate is caused to rotate about its own axis and at the sametime the filiform element is supplied and disposed, repeatedly andcontinuously, along a circumference of prescribed diameter passingthrough the central part of the disc.

Each time the filiform element, during its disposition about saidcircumference, again reaches the rotating disc, one of its sectionsisthreaded into the eyelet the inlet of which at that moment is disposedin correspondence with the supplied filiform element. The eyelet, duringits continuous rotation together with the disc, acts on the sections ofthe element therein threaded and consequently imparts a rotation, aboutan imaginary axis, to the vari-' ous coils of the filiform elementdisposed along the circumference causing them to be twisted, the pitchof the strand being a function of the ratio between the supply speed ofthe filiform element and the speed of rotation of the disc about its ownaxis.

On completion of the helically wound annular structure, the end of thefiliform element secured to the disc is detached and the filiformelement is separated from its source. Then, the ends of the annularstructure are butt-jointed into a means which compels them to remainWOUND Patented May 17, 1966 best means presently contemplated forpracticing the.

method of the invention; wherein:

FIG. 1 is a top plan view of the machine and of the supply device forthe same;

FIG. 2 is a vertical section of the machine on an enlarged scale andtaken on the plane of line 22 of FIG. 1;

FIG. 3 is a fragmentary vertical section taken on line 3-3 of FIG. 1 andalso on an enlarged scale;

FIG. 4 is a vertical section on an enlarged scale through the box 47shown in plan in FIG. 1;

FIG. 5 is a sectional view on line 5-5 of FIG. 4;

FIG. 6 is a sectional view on an enlarged scale taken on line 66 of FIG.2;

FIG. 7 is a front elevational view of the machine and supply device, inwhich some parts are broken away for illustrative purposes;

FIG. 8 is a fragmentary elevational view as seen from the right side ofFIG. 7 but on an enlarged scale;

FIG. 9 is a sectional view, also on an enlarged scale, taken on line 99of FIG. 7;

FIG. 10 is a fragmentary detail onan enlarged scale, with some parts insection, of the carriage assembly of the supply device;

FIG. 11 is a sectional view through the vertical shaftv 4 showing thehydraulic fluid disrtibution system; and

'FIG. 12 is a fragmentary detail on an enlarged scale of a finishedannular structure.

From the accompanying illustrative drawings it will be noted, as bestshown in FIG. 2 thereof, that frame 1 carries by means of the ballbearings 2 and 3 a vertical shaft 4 integral with a revolving platform5. On the shaft 4 there is keyed a bevel gear 6 which meshes with abevel gear 7 keyed on a relatively short horizontalshaft 8 supported inframe 1 by ball bearings 9 and 10. On the shaft 8 there is also keyed agear 11 which is connected through a chain 12 with a gear 13 keyed onthe shaft of a motor 14.

On the platform 5 are assembled two substantially semicircular sectors15 and 16, as best shown in FIG. 1, having one of their endsrespectively pivoted on the pins 17 and 18, integral with the platform5, and the other end respectively pivoted at one end of the levers 19and 20 which, in turn, are pivoted on pivot pin 21 carried by one end ofthe bell-crank lever 22 pivoted at its opposite end of the stem 23 of apiston slidable in a double-acting cylinder 24. The bell-crank lever 22is moreover pivoted at an intermediate point on a pivot pin 25 integralwith the platform 5. The circular sectors 15 and 16 are provided with aperipheral groove 26.

In a support 27 (see FIG. 2) integral with the platform 5, there ismounted, by means of the ball bearings 28 and 29, a shaft 30 to the endof which is keyed a bevelgear 31 meshing with a fixed' gear 32 integralwith the frame of the machine. On the other end of the shaft 30 there iskeyed a gear 33 meshing with a gear 34 (see a FIG. 3) which meshes inturn with a gear 35 keyed at one end of a shaft 36, the length of whichcan be adjusted according to the diameter of the structure to beobtained. Shaft 36 is constituted by two telescopic elements and isassembled in the support 27 by means of the ball bearings 37, 38 and 39.At the other end of the shaft 36 there is keyed a bevel gear 40, meshingwith a bevel gear 41 keyed on a small shaft 42 (see FIG. 6) on whichthere is also keyed a gear 43 meshing with two symmetrical gears 44 and45 assembled respectively on one end of shafts 115 and 114 while on theother end of these shafts are keyed the gears 44 and 45' (see FIG. 2)equal to the gears 44 and 45, which mesh with a slotted crown gearprovided on a disc 46 having two lateral projections 46 (see FIG. 4)slidable along two corresponding guides assembled in a box 47 divisiblein two parts, between which the peripheral part of the disc is inserted.The axis of the disc lies in a vertical plane tangent to thecircumference defined by the sectors 15 and 16.

In the slotted portion of the crown gear of the disc 46 there is aleading edge 48 and an eyelet 49. Near the eyelet 49 there are meansabout to be described fixed on the disc 46, which serve to clamp thefree end of the Wire 60 during the manufacture of the annular structure.

The means for clamping wire 68 to disc 46 is shown in FIGS. 4 and andcomprises a single acting cylinder 116, provided with a hole 117 for theintake and discharge of a compressed fluid, and a spring 118 inserted inits upper head and wound about stem 119, the lower end of the latterbeing connected to a piston 120. Spring 118, it will be noted isfastened to the upper face of the piston 120 and pushes the latter toits lower position when compressed fluid is discharged from the hole117. The upper end of stem 119 is free and when the piston pushes thisstem upwardly, the upper end engages a fork element 121 rotatable aboutpivot 121. The upward rotation of the fork element 12]. causes rotationof element 122 which is rotatable about a pivot 123, and also causescompression of spring 124. Ring 125 is assembled integral with disc 46,and rotation of the element 122 in a clockwise direction detaches thesurface of the latter from the stationary ring 125 whereby the end ofthe wire 60 previously threaded in the eyelet 49 can be inserted betweenthe element 122 and ring 125 and remains clamped therein when thecompressed fluid is discharged from the hole 117 and consequently thespring 118 pushes the piston 120 downward and the spring 124 causes theelement 122 to rotate in a counterclockwise direction.

Three hydraulic cylinders 24,- 50, and 116, illustrated in FIGS. 1, 2,and 4 respectively, are mounted on the revolving platform 5. The meansfor providing fluid under pressure to these cylinders is shown in FIG.11. A fixed box 151) is mounted on the lower end of the rotating shaft4. The box is provided with the necessary bearings 151 and 152 and seals153 to 156. Three connectors 157 to 159 are provided for connecting thebox to a source of fluid under pressure (not shown). Each connector 157to 159 respectively opens directly to an annular chamber 160 to 162which surrounds the lower end of the shaft 4. The shaft 4 is hollow andcontains therein three ducts 163 to 165, the lower ends of which are incommunication with radial ducts 166 to 168 respectively. Each of theradial ducts 166 to 168 is in alignment with one of the annular chambers160 to 162 respectively. The upper end of ducts 163 to 165 are at alevel slightly higher than that of the upper face of the platform 5. Thethree annular chambers are separated by seals 154 and 155. The radialducts 166 to 168 are in constant communication with an annular chamberduring the rotation of the shaft 4 and therefore cylinders 24, 50, and116 may be provided with a constant supply of fluid under pressure.

For purposes of simplification the means described above for clampingthe free end of the wire 60 to the disc 46 have been omitted from FIG.6, while being shown in detail in FIGS. 4 and 5. Moreover, it is pointedout that other less detailed means may be utilized, to secure one end ofthe wire or filiform element directly or indirectly to one face of thedisc; for example, a screw would be sufficient.

Integral with the revolving platform 5 there is also assembled asingle-acting cylinder 50 (see FIG. 2), which slidably receives a piston51 on the upper end of a rod 52 which carries at its lower end a lever53, one end of the latter being pivoted on a pin 54 integral with theplatform 5 and the other end of which is pivoted on the lower end of asmall shaft 55, at the upper end of which there is fastened a blade 56.The small shaft 55 is encircled by a compression spring 57, one end ofwhich bears against a flange 58 mounted on the lower end of shaft 55 andthe other end of which engages a support member 59 integral with theplatform 5.

Referring to FIGS. 3 and 6 it will be noted that there is a saddle 134slidable normal to the plane of the drawing in FIG. 6 by the externallythreaded screw 113 shown in FIG. 3, the screw 113 meshing with aninternal screw thread provided in an adjacent wall of saddle 134. Thelatter is suspended from the rotatable platform 5 by screws 135 and 136supported by the blocks 137 and 138 slidably mounted along guides 139and 140. Also, it will be noted that box 47 is secured to the saddle 134by a plurality of screws 141. Gears 44 and 45 carried on shafts 115 and114 are necessary due to the interruption of the crown wheel of disc 46so that at least one of the gears 44' and 45' is constantly engaged withthe crown wheel.

To supply the wire 60 to the machine there is a bobbin 61 (see FIGS. 7and 9), having a horizontal axis, and supported by a bell-crank arm 62keyed on the upper end of a shaft 63, a .bevel gear 64, on shaft 63meshes with a bevel gear 65 assembled on a horizontal shaft 66 providedwith a flexible coupling 133. A gear 67 on the other end of shaft 66meshes with a gear 68 which meshes in turn with a gear 69 keyed on ahorizontal shaft 71'). On shaft 70 there is also keyed a gear 71connected through a chain 72 with a gear 73 keyed on the shaft of themotor 14. On the supporting stand 74 there is assembled a second motor75 on the horizontal shaft of which there is keyed a pulley 76 connectedby means of a belt 77 to a second pulley 78 keyed on a horizontal shaft79 onto which is also keyed a gear 89, meshing with a gear 81 keyed on ashaft 82. On the front end of the shaft 82 there is keyed a roller 33,cooperating with a roller 84 keyed on the front end of the shaft 79. Thestand 74 supports two vertical rods 85, parallel to each other andprovided with longitudinal guides along which a saddle 86 is slidableand upon which there is rotatably assembled a pulley 87. On a cross bar88 inter-connecting the two rods 85, there is rotatably assembled apulley 89, connected to a rheostat 89, upon which passes a metallic rope90. One end of the metallic rope 90 is connected to a counter weight 126(see FIG. 8) slidable in a vertical guide 127, the other end of the rope90 is secured to the upper part of the saddle 86 slidable along theguides 128 and 129. On one side of the saddle 86 there is a cam 130. Theright vertical rod (see FIG. 8) carries microswitches 131 and 132.Microswitch 131 is actuated by the cam 130 when the festoon iscompletely loaded and stops the motor 75 which controls the supply ofthe wire 60. Microswitch 132 is actuated by the cam 130 when the festoonis completely unloaded, and also stops the motor 75. The purpose ofrheostat 89' is to adjust the speed of motor 75. The stand 74 alsocarries a frusto-conical wire guide 91 and an idle pulley 92.

On a horizontal guide 93 (see FIG. 10) carried by the stand 74 there isslidably assembled a carriage 94, bearing a cylinder 95 provided with atop opening 96 for the introduction and the discharge of compressedfluid acting on a membrane 97 which in turn exerts a pressure lower endof the rod 100 serves to clamp the wire 60 against the bottom wall ofthe carriage 94.

For the purpose of imparting reciprocal sliding of the carriage 94 alongthe guide 93, there is provided a bellenank lever 101 (see FIG..7), thelower end of which is pivoted on the rod 102 of a piston slidable withina double-acting cylinder 103, which latter is pivoted to a fixed pivot104. The upperend of the lever 101 is bifurcated and bears slidablyassembled, a shoe 105 pivoted on a depending projection of the carriage94. The lever 101 is also pivoted at an intermediate point on a fixedpivot 106.

At the end of the horizontal guide 93 there is provided a cutter (seeFIG. l), consisting of a single acting cylinv der 107 having a loweropening 108 for the introduction and the discharge of compressed fluid.The upper end of the rod 109 of the piston 110 which is slidable withinthe cylinder 107, terminates in a blade. Between the piston 110 and theupper part of the cylinder 107 there is inserted a helical spring 111which opposes to the upward movement of the piston 110. Integral withthe cutter, there is a wire guide 112.

In practicing the method for the manufacture of the helically woundannular structures in accordance with the present invention by means ofthe above-described apparatus, the motor 14 (see FIG. 7), through thegears 73 and 71 and the chain 72 and the gears 69, 68, 67, 65 and 64,rotates the arm62 and the bobbin 61 supported thereby about a verticalaxis passing through the axis of the wire-guide 91. This impartsrotation of the wire 60 about its own axis whereby it is paid off fromthe bobbin by virtue of the action of the drawing rollers 83 and 84,whose rotation in opposite directions is controlled by the motor 75 bymaens of the pulleys 76, 78 and the belt 77, and of the gears 80 and 81.Accordingly, the wire passes on the pulley 87 which, by means of therope 90 and of the pulley 89, controls the rheostat 89' and permits byvarying its position on the festoon adjustment of the speed at which thewire is supplied to conform it to the manufacturing speed. Thereafterthe wire passes below the pulley 92, through the cylinder 95, to theupper part of the cutter and to the wire guide 112,

r and is threaded through the eyelet of the disc 46 and clamped on theface of the disc 46 (see FIG. The cylinder 24 (see FIG. 1) haspreviously been filled with compressed fluid introduced from its endopposite to that in which said cylinder is pivoted, whereby the twosectors 15 and 16 are expanded to constitute a circumference.

The revolving platform 5 (see FIG. 2) is caused to rotate by the motor14 which, by means of the gears 11 and 13 and the chain 12 rotates theshaft 8 and therefore the bevel gear 7 which in turn actuates the bevelgear 6 and rotates the shaft 4 upon which the latter is keyed.

The rotation of the shaft 4, besides causing rotation of the platform 5also causes rotation of the support 27 integral with the shaft 4 and ofthe elements supported by support 27. As a result the gear 31 rolls onthe gear 32 which is fastened to the frame 1 and imparts rotation to theshaft 30 and to the gear 33 keyed thereon. In turn, gear 33 drags intorotation the gears 34 and 35 and the shaft 36 as well as through thebevel gears 40 and 41, the small shaft 42 land the gears 43, 44, and 45.As a consequence, rotation is imparted to disc 46 about the axis of thelatter in such a direction as to rotate the wire threaded in the eyeletin the same direction in which it was previously rotated by the arm 62.Therefore, the disc 46 rotates simultaneously about the shaft 4 andabout its own axis.

At each turn of the platform 5 a further section of the wire is threadedin the eyelet 49 of the disc 46 which, rotating continuously togetherwith the disc, acts 6 on the sections of wire contained therein andimparts to the various coils of the wire disposed in the recess 26 ofthe circular sectors :15 and 16 a rotation about an imaginary circularaxis, resulting in a twisting of the wire, the pitch of the strand beinga function of the ratio between the supply speed of the wire and thespeed of rotation of the disc 46 about its own axis. As a result of theprogressive-increasing of the diameter of the helically wound annularstructure, the two circular sectors are subjected to a correspondingrotation about the pivots 17 and 18 whereby the development of therecess 26 is reduced.

When the platform has completed a prescribed number of turns, the motors14 and 75 are stopped and compressed fluid is injected through theopening 96 of the cylinder (see FIG. 10) in order to bring aboutclamping of the wire 60 passing through it by means of the stem 100.Then compressed fluid is also injected through the opening 108 in orderto drive the rod 109 and the associated blade upwardly, t-hus cuttingthe-wire. The blade is lowered immediately afterwards under the actionof the spring 111 due to discharge of the compressed fluid from thecylinder 107. At this time, to remove the resulting annular structurefrom the machine, additional rotation of the sectors 15 and 16 about thepivots 17 and 18 respectively is carried out by means of the pistonslidable within the cylinder 24 to sufficiently reduce the developmentof the circumference previously defined by the recess 26 (see FIG. 1).Furthermore, compressed fluid is injected through the opening 50' of thecylinder 50 (see FIG. 2), to raise the blade 56 which pushes upward theannular structure and causes it to overturn towards the eyelet fromwhich it is unthreaded as soon as its end is removed from the clampingmeans. The blade 56 is immediately retracted into its housing by' thespring 57, which had previously been subjected to compression as aresult of the discharge of compressed fluid from the cylinder 50.

Upon commencing the manufacture of a new annular structure, compressedfluid is injected in the cylinder 24 to again expand the sectors 15 and16 whereby the recess 26 may define a circumference (see FIG. 1), andcompressed fluid is injected in the cylinder 103 from the end at whichit is pivoted on the pivot 104 (see FIG. 10), so that the bell-cranklever 101 may slidably displace the carriage 94 to the left. After theend of the Wire has been suitably clamped to a face of the disc 46,compressed fluid is discharged from the opening 96 in order that thespring 99 may again raise the rod-100 and may free the wire previouslyclamped therein. Also, compressed fluid is discharged from the openingof the cylinder 103 through which it had been previously injected andcompressed fluid is injected through the opposite end of the cylinder103 to move the carriage 94 to the right.

When the resulting annular structure serves as a reinforcing wire forthe beads of the pneumatic tires, the two ends of the wire arebutt-jointed by threading them into the opposite ends of a suitablesleeve or by welding them. FIG. 12 illustrates a fragmentary portion ofa completed annular structure with the ends joined by a sleeve 60'.

The method and the machine as described above have numerous advantagesover those described in the aboveidentified prior application of thesame applicant, primarily due to the elimination of the auxiliary coreabout which the wire is wound, such as:

A notable reduction of the time necessary for manufacturing the annularstructure inasmuch as unthreading the core from the structure oncompletion of the manufacturing operation involved more time than thatrequired to wind the wire about the core, and the consequent possichinessimultaneously;

A marked reduction of waste material, mainly due to the inconstantdevelopment of the core because of the variation of the elastic andmechanical characteristics of the same during use;

A substantial reduction and simplification of the maintenance as thesectors in the cavity of which the annular structure is obtained arerigid and maintain their features;

The possibility of manufacturing annular structures having a remarkablysmaller diameter;

In the utility of a change gear to take into account the greaterthickness of the core in the next turns, due to the presence on the coreof the previously wound wire coils.

It is understood that the principle of the invention remaining unvariedthe details of the machine and the forms of realization of the methodcan be widely varied with respect to what is described and illustratedonly by way of non-limiting example without departing from the scope ofthe invention itself. For example, the disc which determinates byrotating about its own axis the helical winding of the filiform elementcan be provided with several eyelets disposed side by side in order thatthe various sections of the filiform element be separated with respectto one another or the eyelets may have a configuration different fromthat illustrated by the drawings whereby the various sections of thefiliform element are not aligned but have a different disposition.

Furthermore, the disc may be so adjusted that its plane does not passthrough the axis of rotation of the revolving platform. Also, instead ofa single disc, it is possible to provide a plurality of discs, disposedat an equal or different distance along the circumference described bythem during rotation about the axis of the revolving platform, and theplane of these discs may be disposed radially to intersect the plane ofthe others along said axis or have a different adjustment.

Finally, the disc or discs may rotate only about their own axis and thewire can be disposed along the circumference defined by the circularsectors by means of a wire-guide rotating about an axis passing through.the center of the circumference and normal to the plane containing thesame.

What is claimed is:

1. A method for manufacturing annular structures having a continuousfiliform element helically wound about an imaginary circular axis,comprisingthe steps of temporarily fastening one end of said filiformelement to one face of a disc having a central eyelet provided with alateral inlet, rotating said disc about its own axis and simultaneouslyrepeatedly disposing the filiform element along a circumference ofpreestablished diameter passing through the central part of said discwhereby each time the filiform element during its repeated dispositionabout said circumference again reaches the rotating disc, one of itssections is threaded in said eyelet.

2. The method of claim 1, including the step of causing the disc torotate simultaneously about its own axis and about a second axis normalto the first and passing through the center of said circumference alongwhich the filiform element is disposed.

3, The method of claim 1, including the step of disposing the filiformelement about said circumference by rotating a guide about an axispassing through the center of said circumference and normal to a planecomprising the same.

4. A method for manufacturing annular structures having a continuousfiliform element helically wound about an imaginary circular axis,comprising the steps of temporarily fastening one end of said filiformelement to one face of a disc having a central eyelet provided with alateral inlet, rotating said disc simultaneously about its own axis andabout a second axis normal to the first axis and contained in the planeof the disc itself, disposing the filiform element along thecircumference of a circle described by the rotation of said eyelet aboutsaid second axis, the rotating disc threading into said eyelet a sectionof said filiform element during each repeated disposition about saidcircumference.

5. The method according to claim 4 wherein lengths of said filiformelement comprised between two subsequent sections of it threaded in theeyelet are compelled by the rotation of said eyelet to rotate about animaginary axis concentric with respect to said circumference and totwist each other.

6. The method according to claim 4 wherein said filiform element, beforebeing disposed along the circumference, is rotated about its own axis ina direction equal to that according to which it is then rotated by thedisc.

7. The method according to claim 4 wherein upon completion of thehelically wound structure, the ends of the filiform element are fixed ina butt-jointed relationship.

8. A machine for the manufacture of annular structures having acontinuous filiform element helically wound about an imaginary circularaxis comprising a rotatable circular winding form, a radial slot in theperiphery of said form, a rotatable disc mounted in said slot with theaxis of said disc tangential to the periphery of and coplanar with saidform, said disc having a centrally located eyelet, said eyelet providedwith a lateral inlet for receiving at least one section of the filiformelement, means for feeding said filiform element to said disc, means fortemporarilyfastenig one end of the filiform element to one face of saiddisc, means for rotating said disc about its own axis whilesimultaneously rotating said form and said disc about the axis of theformer, whereby said filiform element will be repeatedly disposed aboutsaid form while being rotated about an imaginary circular axis of saidannular structure.

9. A machine according to claim 8 wherein said winding form comprises atleast two adjustable, retractable cylindrical segments, a back plate,said cylindrical segments pivotally mounted on said back plate,retracting means mounted on said back plate and operatively connected tosaid segments, and a groove in the outer peripheral surface of saidcylindrical segments to receive the annular structure during itsmanufacture.

10. A machine according to claim 8 wherein a plurality of eyelets areprovided in said disc disposed side by side in order that the varioussections of the filiform element.

be separated with respect to one another.

11. A machine according to claim 8 wherein the relative speed ofrotation of said form and said disc determines the pitch of the filiformelement on the annular structure.

12. A machine according to claim 8 wherein said filiform element is fedto the machine from a bobbin.

13. A machine according to claim 8 wherein said winding form is providedwith means for removing a finished annular structure therefrom.

14. A machine according to claim 8 wherein means are provided to impartto the filiform element a rotation about its own axis in the samedirection of the rotation subsequently imparted to it by the disc duringthe rotation of the latter about its own axis.

15. A machine according to claim 8 wherein said means for feeding saidfiliform element comprises a revolving arm supporting a bobbin uponwhich said filiform element is wound, said arm being normal to the axisof said bobbin, and means to rotate said arm about an axis normal to theaxis of said bobbin.

16. A machine according to claim 8 wherein mean are provided to supplyat the commencement of each manufacturing cycle one end of the filiformelement to said means for temporary fastening of the same.

17. A machine according to claim 8 wherein said disc is peripherallyprovided with a crown gear which is interrupted in correspondence withthe lateral inlet of said disc and means for rotating said crown gearcomprising the v 9 at least two gears at least one of which is inengagement 1,522,798 1/1925 Beyea 245-15 with said crown gear at alltimes. 1,738,018 12/ 1929 Pfeiffer et a1 15 6422 2,753,678 7/1956 Hansenet a1. 2451.5 References Cited by the Examiner 2 902 033 9 1959 White 1513 UNI D STATES PA NT 5 2,979,109 4/1961- Dieckmann 156-422 1,294,1602/1919 Pratt 245-15 1,522,797 1/1925 Beyea 245 1'5 RICHARDI-HERBST,Pr1mary x

1. A METHOD FOR MANUFACTURING ANNULAR STRUCTURES HAVING A CONTINUOUSFILIFORM ELEMENT HELICALLY WOUND ABOUT AN IMAGINARY CIRCULAR AXIS,COMPRISING THE STEPS OF TEMPORARILY FASTENING ONE END OF SAID FILIFORMELEMENT TO ONE FACE OF A DISC HAVING A CENTRAL EYELET PROVIDED WITH ALATERAL INLET, ROTATING SAID DISC ABOUT ITS OWN AXIS AND SIMULTANEOUSLYREPEATEDLY DISPOSING THE FILIFORM ELEMENT